%0 Journal Article
%A Tenne, D.A.
%A Farrar, A.K.
%A Brooks, C.M.
%A Heeg, T.
%A Schubert, J.
%A Jang, H.W.
%A Bark, C.W.
%A Folkman, C.M.
%A Eom, C.B.
%A Schlom, D.G.
%T Ferroelectricity in nonstoichiometric SrTiO3 films studied by ultraviolet Raman spectroscopy
%J Applied physics letters
%V 97
%@ 0003-6951
%C Melville, NY
%I American Institute of Physics
%M PreJuSER-12005
%P 142901
%D 2010
%Z This work was supported in part by the NSF through Grant Nos. DMR-0705127 (D.A.T.), DMR-0507146 (D.G.S.), ECCS-0708759 (C.B.E.), and DMR-0906443 (C.B.E.) and through the MRSEC program by Grant No. DMR-0820404 (C.M.B), DOE EPSCoR Grant No. DE-FG02-04ER46142 (D.A.T.), and Research Corporation for Science Advancement Grant No. 7134 (D.A.T.).
%X Homoepitaxial Sr1+xTiO3+delta films with -0.2 <= x <= 0.25 grown by reactive molecular-beam epitaxy on SrTiO3 (001) substrates have been studied by ultraviolet Raman spectroscopy. Nonstoichiometry for strontium-deficient compositions leads to the appearance of strong first-order Raman scattering at low temperatures, which decreases with increasing temperature and disappears at about 350 K. This indicates the appearance of a spontaneous polarization with a paraelectric-to-ferroelectric transition temperature above room temperature. Strontium-rich samples also show a strong first-order Raman signal, but the peaks are significantly broader and exhibit a less pronounced temperature dependence, indicating a stronger contribution of the disorder-activated mechanism in Raman scattering. (C) 2010 American Institute of Physics. [doi:10.1063/1.3499273]
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000282765700051
%R 10.1063/1.3499273
%U https://juser.fz-juelich.de/record/12005